This invention relates to a multi-component transfer system for enabling at least two components to be positioned in a mixing chamber for subsequent processing.
In many surgical procedures, particularly orthopedic procedures, it has now become common to affix a prosthesis to a bone or joint structure for improving the strength, rigidity, and movement of the bone/joint structure. Although such prosthetic devices have been widely used, hip joints and knee joints are the most common examples of areas where prosthetic devices are used to reduce or eliminate pain and suffering that exists from typical leg movements.
As part of these operations, it has become common practice to secure the prosthesis to the bone or joint using a cement, formed by intermixing a powder and a liquid. Once intermixed, the two components must be thoroughly blended together to achieve the required consistency for the fully mixed cement, with the fully mixed cement then being loaded into a dispensing apparatus for placement in the desired area for affixing the prosthesis to the desired site.
In most applications, the two components forming the cement are mixed in a mixing vessel and, once fully mixed, are manually transferred from the mixing vessel to a dispensing member. Typically, devices such as caulking guns are employed, for dispensing the fully mixed cement to the precisely desired location of the patient. This process is extremely unpleasant for individuals mixing the cement, since the mixed cement contains an offensive, noxious odor. Furthermore, removal of the mixed cement from the mixing vessel into the caulking gun is cumbersome, time consuming, and has the potential for being mishandled and/or dropped.
Another problem typically encountered with prior art systems is the difficulty encountered with air being entrapped in the mixed cement. The presence of air pockets or air bubbles in the mixed cement is undesirable. Since it is important that the cement added to the bone area for affixing the prosthetic be virtually free of any entrapped air bubbles or air pockets, most prior art systems demand mixing of the powder and liquid under vacuum conditions. As a result, added limitations are incurred on the flexibility of the mixing vessel and the ability to mix the two-part cement mixture in any desired location.
Some prior art systems have enabled the mixing to be performed in one vessel which then is directly connected to a feeding system for enabling the mixed cement to be added to a holding tube for use with the dispensing caulking gun. However, a separate dispensing system is required and extra handling and exposure of the mixed cement to the surrounding personnel is required. Furthermore, care must be exercised during the transfer of the mixed cement to the dispenser, since air is frequently introduced into the cement during this transfer operation as well as the risk of dropping or spilling the material.
More recently, a unitary, fully integrated, bone cement mixing and dispensing system has been attained. This unique achievement is realized by creating a single housing or member which comprises a mixing chamber integrally combined with a delivery chamber or tube. The delivery chamber terminates with a portal through which the mixed bone cement is directly dispensed to any desired location.
In order to provide a mixing chamber which can be operated independently of the delivery chamber, the two chambers of the integrated system are movable between two alternate positions. In the first position, each chamber is sealed from the other, while in the second position, the two chambers are in direct communication with each other.
By employing this new development, the two components forming the bone cement are placed in the mixing chamber and intermixed, with complete assurance that no unmixed bone cement will enter the delivery chamber. Complete mixing of the bone cement is assured by providing, in some embodiments, an integrated counter and display which informs the operator the exact time at which the cement components have been thoroughly intermixed.
Once the two components forming the bone cement are fully intermixed with each other, to provide the desired bone cement product, the integrated, dual chamber system of the present invention is moved from its first sealed position to its second open position, enabling the fully mixed bone cement to be transferred from the mixing chamber directly into the delivery chamber. When desired and under the complete control of the operator, the mixed bone cement is advanced through the delivery chamber to a delivery portal, formed at the terminating end thereof. Then, the fully intermixed bone cement is dispensed through the portal directly to the desired location where the product is to be used.
Although this prior art integrated bone cement mixing and delivery system has been successful in overcoming many prior art problems, one problem that has continued to plague this industry is the difficulty encountered in the delivery, shipment, and transfer of the two components which form the bone cement. As is well-known, bone cement comprises a first component which consists of a dry powder and a second component which consists of a liquid monomer.
These components must be kept separate from each other until the user is ready to intermix the components to form the desired bone cement. Typically, the dry powder is stored in a flexible bag, pouch, or similar container, while the liquid monomer is stored for shipment and handling in a vial or tube, usually formed from glass.
In use, the container holding the dry powder which forms a first component is opened and the powder is placed in the mixing vessel. Then, when creation of the cement is desired, the glass vial or tube holding the liquid monomer is opened and the monomer is added to the powder. Thereafter, the two components are thoroughly intermixed with each other.
In attempting to expedite the opening of the vial or tube holding the liquid monomer, as well as reduce any exposure to the foul odor possessed by the liquid monomer, various prior art systems have been developed for enabling the user to insert the sealed vial or tube into an area of the mixing vessel and then break the vial or tube for releasing the liquid monomer directly into the dry powder.
These prior art systems all require that the broken glass pieces or shards of the vial/tube must be separately retained and prevented from reaching the cement product. In attempting to satisfy this requirement, substantial construction and operational difficulties have occurred with these prior art systems. Furthermore, in other prior art systems, manual addition of the monomer is required, exposing the user to the foul odor of the monomer and the substantial difficulties typically encountered in handling such products.
Therefore, it is a principal object of the present invention to provide a multi-component, product handling and delivering system which controllably enables the liquid monomer to be automatically delivered to the dry powder when desired.
Another object of the present invention is to provide a multi-component, product handling and delivering system having the characteristic features described above which comprises a fully integrated structure which eliminates the requirement for independent transfer of the components which form the mixed cement and eliminates the breakage of any vial or tube.
Another object of the present invention is to provide a multi-component, product handling and delivering system having the characteristic features described above which is easy to use and is virtually fool-proof in its operation.
Another object of the present invention is to provide a multi-component, product handling and delivering system having the characteristic features described above which provides intermixed bone cement virtually devoid of entrapped air pockets or air bubbles.
Another object of the present invention is to provide a multi-component, product handling and delivering system having the characteristic features described above which is easily employed by any individual, free from unwanted odors and product handling difficulties.
Other and more specific objects will in part be obvious and will in part appear hereinafter.
By employing the present invention, all of the prior art difficulties and drawbacks have been overcome and a unique, multi-component, product handling and delivering system is achieved. In the present invention, the two components forming the bone cement are maintained separately from each other until actual intermixing thereof for use is desired, with the liquid monomer being completely dispensed from a sealed unit directly into the mixing vessel in a closed loop manner, without exposure thereof to the user and without breakage of the container holding the liquid monomer.
Throughout the following disclosure of the present invention, the multi-component, product handling and delivery system is detailed as a component of an integrated bone cement mixing and delivery system. Due to the unique attributes and substantial advances that have been achieved by the integrated bone cement mixing and delivery system, the present invention is preferably employed in combination with an integrated bone cement mixing and delivery system. However, the present invention is equally applicable to all mixing vessels for bone cement which may be employed with equal efficacy. Consequently, although specific reference to the integrated bone cement mixing and delivery system is found throughout this disclosure, the invention defined herein can be used with any mixing vessel without departing from the scope of this invention.
In accordance with the present invention, the multi-component, product handling and delivering system comprises a mixing vessel within which the dry powder forming the first component of the bone cement is preferably stored, directly in the mixing vessel for shipment therewith. Alternatively, if desired, the powder material may be contained in a sealed bag, pouch, container, or the like which is opened to dispense the powder directly into the mixing vessel. However, in the preferred embodiment, the powder is stored directly in the mixing vessel ready for use.
In addition, the multi-component, product handling and delivering system comprises a sealed vial or tube on which a cap or closure is mounted, with the second component of the bone cement, namely the liquid monomer, stored therein. In the preferred construction, the cap or closure incorporates a zone or integrally formed area which comprises an elastomeric material, such as elastomeric plastics, rubbers, silicones, and the like.
Caps or closures of this nature are well known in the medical field, with the zone being commonly referred to as a xe2x80x9cseptaxe2x80x9d. Typically, such caps or closures are found on vials or containers incorporating liquid medicines which are dispensed through hypodermic needles or syringes. By piercing the septa with the hypodermic needle or syringe, entry into the vial is attained, without loss of any medicine through the cap or closure. This is due to the ability of the septa to seal about the needle when inserted. In addition, once the syringe has been filled and the needle withdrawn, the septa completely closes the aperture formed by the needle, preventing any leakage of medicine therethrough.
In the present invention, the liquid monomer is contained in a vial or tube which incorporates a cap or closure having a septa-like construction. In this embodiment, the septa-bearing vial or tube completely seals the liquid monomer in the vial while enabling a needle or similar piercing element to enter the septa to gain access to the liquid monomer, without any loss of liquid monomer through the aperture that has been formed.
In order to attain the desired transfer of the liquid monomer from the sealed vial or tube directly into the dry powder, without exposing the user to the liquid monomer, the multi-component product handling and delivering system of the present invention comprises a fluid transfer assembly. The fluid transfer assembly of this invention is constructed for cooperating with the sealed vial or tube containing the liquid monomer and the mixing vessel for completely extracting all of the liquid monomer from the vial/tube in a closed loop operation and directly delivering the liquid monomer into the mixing vessel containing the dry powder. This transfer operation is achieved upon demand by the user, while preventing the liquid monomer from being exposed to the user or to the surrounding area.
In its preferred construction, the present invention, the fluid transfer assembly comprises a housing incorporating two portal bearing mounting collars formed thereon and two cooperating, hollow, piercing elements integrally affixed therewith. In the preferred construction, the two cooperating hollow piercing elements comprise hypodermic needle-like constructions which are coaxially associated with each other to provide a substantially continuous elongated flow path therethrough.
In addition, each piercing element comprises a sharp tip portion constructed for piercing through septa-like materials associated with the mixing vessel and the monomer bearing vial or tube. Furthermore, one piercing element is associated with one mounting collar of the liquid transfer assembly.
In addition, the mixing vessel of the present invention incorporates a first portal for cooperating with one of the mounting collars of the fluid transfer assembly and a second portal constructed for being interconnected to a vacuum source. By employing these elements, a completely closed loop, substantially sealed, delivery of the liquid monomer directly into the dry powder for forming the bone cement in the mixing vessel is attained.
In the preferred construction, the first portal of the mixing vessel, which is constructed for being interengaged with a mounting collar of the fluid transfer assembly, incorporates a small disk formed of elastomeric material mounted therein. By employing elastomeric material such as elastomeric plastics, rubbers, silicones, and the like, the interior of the mixing vessel is maintained completely sealed, accessible only by the insertion of a needle-like device through the disk.
In operation, whenever a user is ready to form the bone cement for use in a particular application, the dry powder is placed in the mixing vessel, unless the dry powder has previously been mounted therein. Then, the liquid monomer containing vial/tube is selected and the first collar of the housing of the fluid transfer assembly is telescopically mounted directly onto the septa-bearing cap or closure of the vial/tube. This telescopic mounting procedure causes the syringe-like piercing element associated therewith to be inserted through the septa, thereby gaining access to the interior of the vial/tube.
Thereafter, the second collar of the housing of the fluid transfer assembly is mounted directly on the collar-receiving portal of the mixing vessel. This mounting procedure causes the second piercing element of the fluid transfer assembly to be inserted through the sealing disk mounted in the portal of the mixing vessel. In this way, direct communication between the interior of the vial/tube and the mixing vessel is established, in a completely closed loop, sealed construction.
Once all of the components are mounted in place, the vacuum connected to the second portal of the mixing vessel is activated causing the liquid monomer to be drawn through the piercing elements of the fluid transfer assembly, causing the liquid monomer to be fed directly onto the dry powder contained in the mixing vessel. Once all of the liquid monomer has been transferred into the mixing vessel, the empty vial/tube is removed, along with the fluid transfer assembly, and mixing of the two components is initiated.
As is evident from the foregoing discussion, the removal of the fluid transfer assembly from the first portal of the mixing vessel causes of the sealing disk mounted therein to be immediately closed, as soon as the piercing element is removed therefrom. As a result, the interior chamber of the mixing vessel is continuously sealed from the surrounding environment, preventing any unwanted foul odors to emanate from the mixing vessel.
The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.